Preview Orders

POST/v1/accounts/{account_id}/orders/preview

Preview the impact of orders without submitting them. For each order the engine evaluates every pre-trade risk check and projects the account’s balances and positions as if the order were fully filled — at the limit price for limit orders and at the current reference price for market orders. Orders are evaluated independently: they do not see each other’s projected fills. Nothing is submitted and no account state changes.

The response carries one result per requested order, in request order. When the request contains more than one order, every order must carry a unique id, which is echoed on its result. An order that cannot be previewed gets an error on its own result without affecting the rest of the batch; the response is still 200 OK — per-order outcomes live only in the rows, and non-2xx statuses are reserved for request-level failures (invalid batch, authorization, engine unavailable).

Path ParametersExpand Collapse

account_id: number

Body ParametersJSONExpand Collapse

preview: array of NewOrderRequest { order_type, quantity, side, 13 more }

order_type: RequestOrderType

Type of order

One of the following:

"MARKET"

"LIMIT"

"STOP"

"STOP_LIMIT"

"TRAILING_STOP"

"TRAILING_STOP_LIMIT"

quantity: string

Quantity to trade. For COMMON_STOCK: shares (may be fractional if supported). For OPTION (single-leg): contracts (must be an integer)

side: Side

Side of the order

One of the following:

"BUY"

"SELL"

time_in_force: RequestTimeInForce

Time in force

One of the following:

"DAY"

"GOOD_TILL_CANCEL"

"IMMEDIATE_OR_CANCEL"

"FILL_OR_KILL"

"GOOD_TILL_DATE"

"AT_OPEN"

"AT_CLOSE"

id: optional string

Optional client-provided unique ID (idempotency). Required to be unique per account.

maxLength64

expires_at: optional string

The timestamp when the order should expire (UTC). Required when time_in_force is GOOD_TILL_DATE.

formatdate-time

extended_hours: optional boolean

Allow trading outside regular trading hours. Some brokers disallow options outside RTH.

instrument_id: optional InstrumentIDOrSymbol

Instrument ID (UUID) or symbol (equity ticker or OSI option symbol). Either symbol or instrument_id must be provided.

minLength1

limit_offset: optional string

Limit offset for trailing stop-limit orders (signed)

limit_price: optional string

Limit price (required for LIMIT and STOP_LIMIT orders)

position_intent: optional RequestPositionEffect

Optional open/close intent for this order. When omitted, the platform determines the position effect.

One of the following:

"OPEN"

"CLOSE"

stop_price: optional string

Stop price (required for STOP and STOP_LIMIT orders)

strategy: optional OrderStrategy

Optional execution strategy. One of SOR, VWAP, TWAP, or DMA. Defaults to SOR, the only strategy OTC common-stock orders support. VWAP and TWAP are supported only on MARKET and LIMIT orders, and DMA only on LIMIT orders; all three require DAY time-in-force. VWAP, TWAP, and DMA do not support extended_hours.

One of the following:

Type object { type }

Smart Order Router. Routes the order to the best available venue(s).

type: "SOR"

Execution strategy type.

object { type, end_at, start_at }

Volume-Weighted Average Price. Works the order to track the volume-weighted average price over the execution window.

type: "VWAP"

Execution strategy type.

end_at: optional string

UTC timestamp (RFC 3339) by which to finish working the order. Defaults to market close.

formatdate-time

start_at: optional string

UTC timestamp (RFC 3339) at which to begin working the order. Defaults to the time the order is received.

formatdate-time

object { type, end_at, start_at }

Time-Weighted Average Price. Spreads execution evenly across the execution window.

type: "TWAP"

Execution strategy type.

end_at: optional string

UTC timestamp (RFC 3339) by which to finish working the order. Defaults to market close.

formatdate-time

start_at: optional string

UTC timestamp (RFC 3339) at which to begin working the order. Defaults to the time the order is received.

formatdate-time

object { destination, type }

Direct Market Access. Routes the order straight to the named venue.

destination: string

Venue code the order is routed to.

type: "DMA"

Execution strategy type.

symbol: optional string

Trading symbol. For equities, use the ticker symbol (e.g., “TSLA”). For options, use the OSI symbol (e.g., “TSLA 250117C00190000”). Either symbol or instrument_id must be provided.

trailing_offset: optional string

Trailing offset amount (required for trailing orders)

trailing_offset_type: optional TrailingOffsetType

Trailing offset type (PRICE or PERCENT_BPS)

One of the following:

"PRICE"

"BPS"

ReturnsExpand Collapse

data: OrderPreviewEntryList { UnionMember0, UnionMember1 }

One of the following:

object { preview, id }

The order was previewed successfully.

preview: OrderPreview { account_id, amount, buying_power, 5 more }

The projected impact of the order.

account_id: number

The account the order was previewed for.

formatint64

amount: OrderPreviewAmount { gross_amount, net_amount }

Monetary size of the previewed order.

gross_amount: string

Total cash impact of the order before estimated fees and commissions.

net_amount: string

Total cash impact of the order after estimated fees and commissions.

buying_power: OrderPreviewDelta { after, before, change }

Buying power before and after the order.

after: string

The value with the previewed order also fully filled.

before: string

The value before the order, as the risk engine evaluates it: the account’s open orders are projected as filled.

change: string

The previewed order’s isolated impact: after - before.

currency: string

Currency for all monetary values.

equity: OrderPreviewDelta { after, before, change }

Account equity before and after the order.

after: string

The value with the previewed order also fully filled.

before: string

The value before the order, as the risk engine evaluates it: the account’s open orders are projected as filled.

change: string

The previewed order’s isolated impact: after - before.

errors: array of OrderPreviewError { description, metadata, type }

Risk-check errors that would prevent the order from being accepted. Empty when the order would pass every pre-trade risk check.

description: string

Human-readable description of the error.

metadata: map[string]

Structured details for the error (stringified values), e.g. required and available amounts, and leg_index/leg_symbol for multileg leg errors.

type: string

Stable error code.

margin_details: OrderPreviewMarginDetails { initial_margin_excess, initial_margin_requirement, maintenance_margin_excess, 3 more }

Margin requirements and excess before and after the order.

initial_margin_excess: OrderPreviewDelta { after, before, change }

Initial margin excess.

after: string

The value with the previewed order also fully filled.

before: string

The value before the order, as the risk engine evaluates it: the account’s open orders are projected as filled.

change: string

The previewed order’s isolated impact: after - before.

initial_margin_requirement: OrderPreviewDelta { after, before, change }

Initial margin requirement.

after: string

The value with the previewed order also fully filled.

before: string

The value before the order, as the risk engine evaluates it: the account’s open orders are projected as filled.

change: string

The previewed order’s isolated impact: after - before.

maintenance_margin_excess: OrderPreviewDelta { after, before, change }

Maintenance margin excess.

after: string

The value with the previewed order also fully filled.

before: string

The value before the order, as the risk engine evaluates it: the account’s open orders are projected as filled.

change: string

The previewed order’s isolated impact: after - before.

maintenance_margin_requirement: OrderPreviewDelta { after, before, change }

Maintenance margin requirement.

after: string

The value with the previewed order also fully filled.

before: string

The value before the order, as the risk engine evaluates it: the account’s open orders are projected as filled.

change: string

The previewed order’s isolated impact: after - before.

overnight_margin_excess: OrderPreviewDelta { after, before, change }

Overnight margin excess.

after: string

The value with the previewed order also fully filled.

before: string

The value before the order, as the risk engine evaluates it: the account’s open orders are projected as filled.

change: string

The previewed order’s isolated impact: after - before.

overnight_margin_requirement: OrderPreviewDelta { after, before, change }

Overnight margin requirement.

after: string

The value with the previewed order also fully filled.

before: string

The value before the order, as the risk engine evaluates it: the account’s open orders are projected as filled.

change: string

The previewed order’s isolated impact: after - before.

positions: array of OrderPreviewPosition { instrument_id, quantity, symbol }

Positions in the traded instruments before and after the order.

instrument_id: string

The instrument’s identifier.

formatuuid

quantity: OrderPreviewDelta { after, before, change }

Net position quantity before and after the order.

after: string

The value with the previewed order also fully filled.

before: string

The value before the order, as the risk engine evaluates it: the account’s open orders are projected as filled.

change: string

The previewed order’s isolated impact: after - before.

symbol: string

The instrument’s symbol.

id: optional string

The client-provided id of the order this entry belongs to, echoed from the request. Always present when the request contains more than one order, since ids are required there.

object { error, id }

The order could not be previewed. Shaped exactly like the top-level error object on rejected submissions.

error: APIError { code, message, details }

Why this order’s preview failed.

code: number

The error code is used to identify the nature of the error. It corresponds to an HTTP status code.

formatint32

minimum0

message: string

A human-readable message providing more details about the error.

details: optional array of map[unknown]

Additional error details, if any. This can include structured information such as field violations or error metadata.

id: optional string

The client-provided id of the order this entry belongs to, echoed from the request. Always present when the request contains more than one order, since ids are required there.

Preview Orders

curl https://api.clearstreet.com/v1/accounts/$ACCOUNT_ID/orders/preview \
    -H 'Content-Type: application/json' \
    -H "Authorization: Bearer $API_KEY" \
    -d '[
          {
            "order_type": "LIMIT",
            "quantity": "100",
            "side": "BUY",
            "time_in_force": "DAY",
            "id": "preview-1",
            "expires_at": "2025-10-15T16:00:00.000000000Z",
            "extended_hours": true,
            "instrument_id": "x",
            "limit_offset": "0.50",
            "limit_price": "100.00",
            "position_intent": "OPEN",
            "stop_price": "52.00",
            "strategy": {
              "type": "SOR"
            },
            "symbol": "AAPL",
            "trailing_offset": "2.00",
            "trailing_offset_type": "PRICE"
          },
          {
            "order_type": "LIMIT",
            "quantity": "10",
            "side": "BUY",
            "time_in_force": "DAY",
            "id": "preview-2",
            "expires_at": "2025-10-15T16:00:00.000000000Z",
            "extended_hours": true,
            "instrument_id": "x",
            "limit_offset": "0.50",
            "limit_price": "250.00",
            "position_intent": "OPEN",
            "stop_price": "52.00",
            "strategy": {
              "type": "SOR"
            },
            "symbol": "TSLA",
            "trailing_offset": "2.00",
            "trailing_offset_type": "PRICE"
          }
        ]'

{
  "data": [
    {
      "id": "preview-1",
      "preview": {
        "account_id": 19816,
        "amount": {
          "gross_amount": "10000.00",
          "net_amount": "10000.00"
        },
        "buying_power": {
          "after": "190000.00",
          "before": "200000.00",
          "change": "-10000.00"
        },
        "currency": "USD",
        "equity": {
          "after": "100000.00",
          "before": "100000.00",
          "change": "0.00"
        },
        "errors": [],
        "margin_details": {
          "initial_margin_excess": {
            "after": "95000.00",
            "before": "100000.00",
            "change": "-5000.00"
          },
          "initial_margin_requirement": {
            "after": "5000.00",
            "before": "0.00",
            "change": "5000.00"
          },
          "maintenance_margin_excess": {
            "after": "97500.00",
            "before": "100000.00",
            "change": "-2500.00"
          },
          "maintenance_margin_requirement": {
            "after": "2500.00",
            "before": "0.00",
            "change": "2500.00"
          },
          "overnight_margin_excess": {
            "after": "95000.00",
            "before": "100000.00",
            "change": "-5000.00"
          },
          "overnight_margin_requirement": {
            "after": "5000.00",
            "before": "0.00",
            "change": "5000.00"
          }
        },
        "positions": [
          {
            "instrument_id": "a1a2a3a4-b1b2-c1c2-d1d2-d3d4d5d6d7d8",
            "quantity": {
              "after": "100",
              "before": "0",
              "change": "100"
            },
            "symbol": "AAPL"
          }
        ]
      }
    },
    {
      "error": {
        "code": 400,
        "message": "Security not found: BADSYM"
      },
      "id": "preview-2"
    }
  ],
  "metadata": {
    "request_id": "d3e5b1a2-8c4f-4b6e-9d2a-1f0c9b8a7654"
  }
}

{
  "data": [
    {
      "id": "preview-1",
      "preview": {
        "account_id": 19816,
        "amount": {
          "gross_amount": "10000.00",
          "net_amount": "10000.00"
        },
        "buying_power": {
          "after": "190000.00",
          "before": "200000.00",
          "change": "-10000.00"
        },
        "currency": "USD",
        "equity": {
          "after": "100000.00",
          "before": "100000.00",
          "change": "0.00"
        },
        "errors": [],
        "margin_details": {
          "initial_margin_excess": {
            "after": "95000.00",
            "before": "100000.00",
            "change": "-5000.00"
          },
          "initial_margin_requirement": {
            "after": "5000.00",
            "before": "0.00",
            "change": "5000.00"
          },
          "maintenance_margin_excess": {
            "after": "97500.00",
            "before": "100000.00",
            "change": "-2500.00"
          },
          "maintenance_margin_requirement": {
            "after": "2500.00",
            "before": "0.00",
            "change": "2500.00"
          },
          "overnight_margin_excess": {
            "after": "95000.00",
            "before": "100000.00",
            "change": "-5000.00"
          },
          "overnight_margin_requirement": {
            "after": "5000.00",
            "before": "0.00",
            "change": "5000.00"
          }
        },
        "positions": [
          {
            "instrument_id": "a1a2a3a4-b1b2-c1c2-d1d2-d3d4d5d6d7d8",
            "quantity": {
              "after": "100",
              "before": "0",
              "change": "100"
            },
            "symbol": "AAPL"
          }
        ]
      }
    }
  ],
  "metadata": {
    "request_id": "d3e5b1a2-8c4f-4b6e-9d2a-1f0c9b8a7654"
  }
}

Returns Examples

{
  "data": [
    {
      "id": "preview-1",
      "preview": {
        "account_id": 19816,
        "amount": {
          "gross_amount": "10000.00",
          "net_amount": "10000.00"
        },
        "buying_power": {
          "after": "190000.00",
          "before": "200000.00",
          "change": "-10000.00"
        },
        "currency": "USD",
        "equity": {
          "after": "100000.00",
          "before": "100000.00",
          "change": "0.00"
        },
        "errors": [],
        "margin_details": {
          "initial_margin_excess": {
            "after": "95000.00",
            "before": "100000.00",
            "change": "-5000.00"
          },
          "initial_margin_requirement": {
            "after": "5000.00",
            "before": "0.00",
            "change": "5000.00"
          },
          "maintenance_margin_excess": {
            "after": "97500.00",
            "before": "100000.00",
            "change": "-2500.00"
          },
          "maintenance_margin_requirement": {
            "after": "2500.00",
            "before": "0.00",
            "change": "2500.00"
          },
          "overnight_margin_excess": {
            "after": "95000.00",
            "before": "100000.00",
            "change": "-5000.00"
          },
          "overnight_margin_requirement": {
            "after": "5000.00",
            "before": "0.00",
            "change": "5000.00"
          }
        },
        "positions": [
          {
            "instrument_id": "a1a2a3a4-b1b2-c1c2-d1d2-d3d4d5d6d7d8",
            "quantity": {
              "after": "100",
              "before": "0",
              "change": "100"
            },
            "symbol": "AAPL"
          }
        ]
      }
    },
    {
      "error": {
        "code": 400,
        "message": "Security not found: BADSYM"
      },
      "id": "preview-2"
    }
  ],
  "metadata": {
    "request_id": "d3e5b1a2-8c4f-4b6e-9d2a-1f0c9b8a7654"
  }
}

{
  "data": [
    {
      "id": "preview-1",
      "preview": {
        "account_id": 19816,
        "amount": {
          "gross_amount": "10000.00",
          "net_amount": "10000.00"
        },
        "buying_power": {
          "after": "190000.00",
          "before": "200000.00",
          "change": "-10000.00"
        },
        "currency": "USD",
        "equity": {
          "after": "100000.00",
          "before": "100000.00",
          "change": "0.00"
        },
        "errors": [],
        "margin_details": {
          "initial_margin_excess": {
            "after": "95000.00",
            "before": "100000.00",
            "change": "-5000.00"
          },
          "initial_margin_requirement": {
            "after": "5000.00",
            "before": "0.00",
            "change": "5000.00"
          },
          "maintenance_margin_excess": {
            "after": "97500.00",
            "before": "100000.00",
            "change": "-2500.00"
          },
          "maintenance_margin_requirement": {
            "after": "2500.00",
            "before": "0.00",
            "change": "2500.00"
          },
          "overnight_margin_excess": {
            "after": "95000.00",
            "before": "100000.00",
            "change": "-5000.00"
          },
          "overnight_margin_requirement": {
            "after": "5000.00",
            "before": "0.00",
            "change": "5000.00"
          }
        },
        "positions": [
          {
            "instrument_id": "a1a2a3a4-b1b2-c1c2-d1d2-d3d4d5d6d7d8",
            "quantity": {
              "after": "100",
              "before": "0",
              "change": "100"
            },
            "symbol": "AAPL"
          }
        ]
      }
    }
  ],
  "metadata": {
    "request_id": "d3e5b1a2-8c4f-4b6e-9d2a-1f0c9b8a7654"
  }
}